T-score expresses the certainty with which we can argue that there is an association between the words, i.e. their co-occurrence is not random. The value is affected by the frequency of the whole collocation which is why very frequent word combinations tend to reach a high T-score despite not being significant collocations.
When comparing the T-score and MI score, in most cases
T-score is more useful than MI score. However, both of these scores are affected by the corpus size. This makes them less useful when working with modern mutli-billion-word corpora. This is why Sketch Engine prefers the
LogDice score in most situations, especially in
word sketches.
see
Concordance - collocations
see
Statistics in Sketch Engine
compare
MI Score
logDice